Exploration of benthic diatom indices to evaluate water quality in rivers in the Dongjiang basin Benthic Diatoms from the Tidal Flat of Shanghai, China, during 2005 Summer Species Diversity and Temporal-spatial Distribution of Benthic Diatoms in Jianjiang River, Guangdong Province Comparison of Benthic Diatom Assemblages from Mangrove and Reed Wetland in Qi’ao Island, Zhuhai, Guangdong Province, China DISTRIBUTION OF CHLOROPHYLL AND BENTHIC DIATOMS IN THE INTERTIDAL FLAT AROUND XIAMEN